1976, Manila, the Philippines: Fishermen hauling great silver flounder by the docks, men with afros and patterned button-downs playing cards, a young woman abused by her mother and her mother’s lover. Insiang (Hilda Koronel), the titular character of the first Filipino film to show at Cannes, fits a Cinderella archetype—the luminously beautiful girl oppressed by a cruel family. But the similarities end there. This is not a Hollywood film with a clean, moralizing ending. With a fearsome narrative alchemy, Insiang transforms from a montage of life in Manila’s slums into one of the most brutal, gruesome films I’ve seen.

Insiang lives with her mother Tonya and Tonya’s lover, Dado, in a shack no bigger than, say, a dorm room. Life itself is claustrophobic. Day in and day out, her mother orders her to cook, clean, and wash for the three of them. She’s trapped—in one scene, she grips the bars of a street vendor’s stall like a prisoner. Then, Dado rapes her. He justifies the rape, claiming to Tonya, “You know what she does when you’re not around? She bathes naked and lies nude in bed! I’m just a man, Tonya. Who’ll not be seduced?” Tonya, incensed at her daughter’s alleged promiscuity, throws Insiang out into the streets. When, afterward, a local young man professes love for her, Insiang gives him her trust and her body—only for him to betray and leave her as well.

Insiang’s ultimate revenge on these three is often employed to characterize the film as a feminist film, but I’m not certain her violent retribution results in triumph. As she embarks on her revenge, the film darkens, and in contrast to her earlier clear eyes and soft, glowing complexion, Insiang’s face is presented half in shadow, her eyes black and glittering. She is no longer beautiful but demonic. Her terrible and bloody revenge does not fulfill her, and at the end of the film she seems to wake from a terrible dream and weeps with regret. Violence destroys the lives of her oppressors, but also her own.

As with other social dramas from the period, Insiang ruthlessly exposes how the slums of the Philippines thoroughly consumed its inhabitants. Insiang’s story, though fictional (adapted from a teleplay by Mario O’Hara), was likely emotionally and socially true for many women living in poverty then. And her entrapment in a horrific situation is indicative of a larger social dilemma: How do people escape the slums? A teenager tells Insiang his biggest wish is to make enough money to leave and get a job somewhere far away. That’s why he studies so hard, he says. Dado, too, talks about finding a new job elsewhere. Escape via work is a hope, however tiny, for the men of the neighborhood. But the women? Insiang clutches those bars, saying nothing.

Insiang’s shocking opening scene in some sense epitomizes the entire film. A pig screams and kicks as it’s slaughtered in a factory. Its shrieks sound like a human’s at first. The lack of CGI or studio wizardry makes it safe to assume that this is a real, live pig being killed on camera, and its blood dribbles all over the factory worker, who may or may not actually be an actor. This visceral, documentary-like tone remains for the rest of the film. It may present a fictional story, but its pictures of suffering are authentic. From the slaughter scene, the film cuts to a group of children playing by the shore, undisturbed during the pig’s tortured death. Horror and pain wreak havoc. A child finds a seashell. Life goes on.

Insiang screened in a new restoration as part of the 53rd New York Film Festival at the Film Society at Lincoln Center. Insiang also screens at the Museum of Modern Art October 28-November 3.